Earlier this month, Aquino urged the Association of Southeast Asian Nations to arrive at a common stand on the Spratly's issue, according to the GMA Network.

Aside from the Philippines and China, there are four other claimants to the Spratlys: Malaysia, Vietnam, Taiwan, and Brunei.

The United States also expressed concern over the growing tensions, the AP said.

"We urge all parties to exercise full restraint and seek a diplomatic resolution," a State Department source told the AP.

The Chinese said the fishing vessels sought shelter from a storm in the lagoon, The New York Times reported.

“A Philippine Naval gunboat blocked the entrance of the lagoon, and sent 12 Philippine soldiers, six of which armed, into the lagoon and harassed the Chinese fishermen,” a statement from the Chinese embassy said, according to The Times.